Effect of ball milling duration on the morphology and densification of pineapple pomace pellets

Muhammad Syakir Wan Mohd Luzi; Nur Salihah Alias; Alia Syafiqah Abdul Hamed; Aima Ramli; Nora Salina Md Salim.

Pineapple pomace is an abundant processing residue with potential for conversion into compact pellets suitable for handling, storage and downstream utilization. This study investigated the effect of ball-milling duration on the morphology and densification of pineapple pomace pellets. The milling duration was varied to 0, 30, 60, and 90 min, and the samples were then compacted into pellets. The resulting pellets were characterized for thickness, density, Shore D hardness, surface morphology and color. Increasing milling duration reduced pellet thickness and increased pellet density by approximately 30% and 13%, respectively. Pellet hardness also increased with milling duration, indicating greater resistance to surface indentation. Surface morphology revealed progressive surface smoothing with increasing milling duration. Color analysis showed that increased milling durations improved the pellet color uniformity. These findings demonstrate that ball milling is an effective mechanical pretreatment approach for improving the densification of agricultural biomass residues.

KEYWORDS: Ball milling; Pellet; Pineapple pomace; Scanning electron microscopy



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